がん患者における嚥下障害

引き続き、5th Cachexia Conferenceの資料の中から、がん患者における嚥下障害の抄録を紹介します。

http://www.lms-events.com/19/5th_Cachexia_Conference_2009_Abstracts.pdf

頭頚部がんや化学療法に伴う口腔粘膜の口内炎では、7日以上必要エネルギー量を経口摂取できないようなら、経管栄養（経鼻経管か胃ろう）が推奨されています。

この時期に経口摂取と末梢静脈栄養のみで必要エネルギー量を満たせない状況が続くと、嚥下障害と栄養障害の悪循環に入ると記載されています。この悪循環を避けることはとても重要です。

抄録には記載はありませんが、飢餓や悪液質で嚥下筋の筋萎縮が進むことによる嚥下障害（広義のサルコペニアによる嚥下障害）の問題は大きいと私は考えています。その結果、さらに飢餓が進み嚥下障害も悪化する悪循環の場合、リハだけの対応では不十分です。当然、リハ栄養管理が必要です。

抄録の最後には粘膜炎、口内炎に対する治療として、グルタミンによる治療が選択肢の1つとなる、ただしランダム化比較試験での検証が必要と記載されています。グルタミンはGFOとして禁食時の腸管粘膜の維持目的にて使用されますが、粘膜炎の治療として使用する発想は全くありませんでした。粘膜つながりですね。

The problem of dysphagia in cancer patients
Alessandro Laviano
Department of Clinical Medicine, Sapienza University, Rome, Italy

In cancer patients, the progressive onset of cachexia is related to the combined negative effects of reduced food intake and changes in metabolism of peripheral tissues. In some type of cancers, the relative impact of
reduced food intake may outweigh the contribution of metabolic derangements. In patients with head and neck cancer, dysphagia is the major factor impeding the meeting of energy and protein requirements. In this clinical setting, it is imperative that appropriate actions are taken to prevent the progressive decline of energy intake (i.e., positioning of feeding tube, or PEG). Dysphagia may also occur because of the toxicity associated to the active anti-tumor treatment. During chemotherapy and/or radiotherapy, severe mucositis may occur, limiting energy intake. If persisting for more than 7 days, inability to meet the energy and protein requirements should be treated by enteral nutrition via feeding tube or PEG. If appropriate actions are not taken, then a vicious circle may occur: dysphagia leads to malnutrition which in turn increases susceptibility to treatment-associated toxicity and thus exacerbates dysphagia.

Limiting the toxicity of treatment-associated toxicity is a scientific and clinical challenge which is actively and intensively pursued. Although reports have been published suggesting that short-term fasting may reduce
chemotherapy-associated toxicity, at least in animal models, it appears that a number of nutraceuticals may modulate mucositis. In this light, the use of glutamine may represent a therapeutic option which should be
tested in randomized clinical trials.

References:
Cady J. Nutritional support during radiotherapy for head and neck cancer: the role of prophylactic feeding tube placement. Clin J Oncol Nurs 2007; 11:875-80
van den Berg MG, Rasmussen-Conrad EL, Gwasara GM, Krabbe PF, Naber AH, Merkx MA. A prospective study on weight loss and energy intake in patients with head and neck cancer, during diagnosis, treatment and revalidation. Clin Nutr 2006; 25:765-72
Arends J, Bodoky G, Bozzetti F, Fearon K, Muscaritoli M, Selga G, van Bokhorst-de van der Schueren MAE, von Meyenfeldt M, et al. ESPEN guidelines on enteral nutrition: non-surgical oncology. Clin Nutr 2006; 25:245-59
Bozzetti F, Arends J, Lundholm K, Micklewright A, Zurcher G, Muscaritoli M. ESPEN guidelines on parenteral nutrition: non-surgical oncology. Clin Nutr 2009; 28:445-54